Propane tanks fuel many exciting and entertaining endeavors, from campers to barbecues. Propane tanks hold both liquid and gas fuel, and chemical reactions between the two are what heat our hot dogs and cheeseburgers on the grill. Many tanks include gauges so that you can tell when you need to refill the tank, but if you don't have a gauge and are worried about the propane level before your next use, there are a couple of ways you can check the level yourself.
Search the tank for the letters "TW." This acronym stands for tare weight, or the weight of the tank when there is no propane within it. The letters will be followed by a number, such as "TW 15." This means the tank weighs 15 pounds without propane.
Place your propane tank on a scale, and allow it to settle for a few seconds. Note the pound reading on the scale.
Compare the pound reading with the TW number. Every pound over the TW number represents a pound of propane remaining in the tank. The amount of time the remaining pounds will last varies by size of grill, type of burner and duration of use.
Bring a pot of water to boil on a stove. You must have enough water to coat your propane tank when the water is poured.
Set the propane tank on a completely flat surface. Carefully pour the boiling water over the propane tank. Allow 10 to 15 seconds for the water to cover the whole surface.
Carefully feel the sides of the propane tank until you reach a point at which the tank is hot on the top and colder below. That line indicates the top of the propane level. Propane is so cold that the tank cannot stay hot even under the boiling water.